Quantum Monte Carlo without random numbers

ORAL

Abstract

Real-time diagrammatic quantum Monte Carlo (DiagQMC) is one of the few methods able to treat quantum impurity problem out of equilibrium. Like all Monte Carlo methods, it remains hindered by a convergence rate of one over square root of the number of calculated points (1/N0.5). In recent work, we replaced the Metropolis algorithm and adapted DiagQMC to a Quasi-Monte Carlo integration method, where integration is performed using deterministic low discrepancy sequences [1]. We obtained convergence rate of one over the number of calculated points (1/N) and showed speed-ups of several orders of magnitude for favourable parameters.
In this talk, I will present novel results where the quantum impurity is embedded in a non-trivial environment, such as electron interferometer.

[1] Phys. Rev. Lett. 125 047702 (2020)

*Funding from FLAG-ERA Gransport.

Presenters

  • Marjan Maček

    • CEA Grenoble

Authors

  • Marjan Maček

    • CEA Grenoble
  • Philipp Dumitrescu

    • Center for Computational Quantum Physics, Flatiron Institute
    • Simons Foundation
    • Center for Computational Quantum Physics, Flatiron Institute, 162 5th Avenue, New York, NY 10010, USA
  • Corentin Bertrand

    • Simons Foundation
    • Center for Computational Quantum Physics, Flatiron Institute, 162 5th Avenue, New York, NY 10010, USA
  • Bill Triggs

    • Laboratoire Jean Kuntzmann
    • Laboratoire Jean Kuntzmann, Université Grenoble Alpes, CNRS, 38401 Grenoble, France
  • Olivier Parcollet

    • Center for Computational Quantum Physics, Flatiron Institute
    • Center of Computational Quantum Physics, Flatiron Institute, New York City, USA
    • Center for Computational Quantum Physics, Flatiron institute
    • Simons Foundation
    • Center for Computational Quantum Physics, Flatiron Institute, 162 5th Avenue, New York, NY 10010, USA
  • Xavier Waintal

    • Univ. Grenoble Alpes, CEA, IRIG-PHELIQS, 38000 Grenoble, France
    • Université Grenoble Alpes
    • CEA Grenoble
    • Université Grenoble Alpes, CEA, IRIG-PHELIQS, 38000 Grenoble, France